Datasheet

Installation www.ti.com
The analog input goes into the HP-IN headphone jack. Plug the headphones or line-driver load into the
HP-OUT headphone jack. Use a PWM input signal by installing C2, C3, C5, and C6 onto the EVM.
Pressing the HP-SD button on the EVM shuts down the headphone amplifier/line-driver.
2.1.5 USB Interface
The TAS5721 and TAS5723 device registers are accessed through I
2
C bus lines SDA and SCL. The USB
circuit and USB connector on the Input-USB Board3 board facilitate the connection between a host
computer and the device. The EVM USB circuit is powered by the 5-V USB line of the host PC and is
independent of the PSU available on the board. The USB device is a TAS1020B from Texas Instruments.
The USB input streams audio. Toggling switch S7 to USB selects the USB I2S source over the SPDIF
source.
2.1.6 Digital Audio Interface SPDIF
The Digital Audio Interface SPDIF (RCA/OPTO) accepts digital audio data using the I
2
S protocol. See the
TAS5721 or TAS5723 data sheet for more information.
The RCA connector and the OPTO connector are the two SPDIF interfaces on the Input-USB Board3. The
switch, S2, toggles between the OPTO and RCA connector (RCA connector labeled as COAX)
accommodating the signal source. When the RCA cable or optical cable is connected and the signal
source is powered up, verify that the SPDIF lock indicator LED illuminates, confirming that a viable signal
is available to the device. Use switch S7 to connect the SPDIF to the digital source SDIN1.
2.1.7 ADC Interface
The PCM1808 ADC is used to convert an analog audio signal to a digital signal for the TAS5721 or
TAS5723. The DIR9001 still provides clock signals to the ADC in this process. A 12.288-MHz crystal is
installed on the Input-USB Board3. The ADC is an additional feature of this board providing flexibility in
sourcing an audio signal to the TAS5721 or TAS5723. Review the PCM1808 data sheet (SLES177) for a
detailed description of the ADC on this EVM. The PCM1808 only accepts up to a 1-V
RMS
input signal.
Uninstalling jumpers JP300 and JP301 implements a voltage divider that halves the incoming voltage,
allowing input of up to a 2-V
RMS
signal through the ADC1-IN audio jack.
The EVM uses only one analog input jack, the ADC1-IN. If an analog input is connected, it takes
precedence over any digital audio signal.
2.1.8 General Guidelines for Powering-Up the Board
Connect the Input-USB Board3 and the EVM boards by locating pin 1 on each board, indicated by a small
white triangle. The Input-USB Board3 plugs down onto the EVM board (the TAS5721-TAS5727EVM board
fits underneath the Input-USB Board3). Pin 1 on each board must be connected to each other.
Install the EVM software on the PC before powering up the board. After connecting the loudspeakers or
other loads, PSU, and the data line, power up the PVDD power supply first; then power up the 12-V V
IN
power supply.
2.2 Software Installation
Download the TAS57XX Control Console GDE from the TI Web site, located on the TAS5721-
TAS5727EVM product page. The TI Web site always has the latest release and any updates to versions
of the GUI.
Execute the GUI install program, Setup.exe. Once the program is installed, the program group and
shortcut icon is created in Start → Program → Texas Instruments Inc → ControlConsole.
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TAS5721-TAS5723EVM Evaluation Module SLOU346–July 2012
Copyright © 2012, Texas Instruments Incorporated